<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <title>版心布局</title>
  <style>
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    html,body{
      height: 100%;
      background-color: #ccc;
    }
    main{
      width: 1200px;
      height: 100%;
      margin: 0 auto;
      font-size: 40px;
      background-color: pink;
    }
    header{
      height: 80px;
      background-color: aqua;
    }
  </style>
</head>

<body>
  <main>
    <header>版心</header>
    <section>内容</section>
  </main>
</body>
</html>